CN111200483A

CN111200483A - Antenna code word cooperative optimization method for multi-antenna transmission diversity

Info

Publication number: CN111200483A
Application number: CN201911417582.2A
Authority: CN
Inventors: 卜智勇; 王爽; 周斌
Original assignee: Chengdu Zhongke Micro Information Technology Research Institute Co Ltd
Current assignee: Chengdu Zhongke Micro Information Technology Research Institute Co Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-05-26

Abstract

The invention discloses an antenna code word collaborative optimization method for multi-antenna transmit diversity, which comprises the following steps: s1, selecting a coding matrix of the multi-antenna transmission diversity; s2, analyzing the orthogonality of the code words in the coding matrix; s3, designing a transmitting antenna structure suitable for the quasi-orthogonal coding matrix; s4, calculating the isolation between the transmitting antenna array surfaces; s5, code word optimal allocation based on the isolation degree of the transmitting antenna array surface; and S6, the method is suitable for optimal transmission of the quasi-orthogonal coding matrix and the like. The invention is applied to a multi-antenna transmission system, realizes full-rate full-diversity transmission of signals through multi-antenna code word collaborative optimization allocation, achieves full-diversity gain and full-rate transmission of the transmission system in the multi-antenna transmission system, obviously reduces the calculated amount, solves the adverse effect of non-orthogonal code words in multi-antenna transmission diversity transmission, and can effectively improve the crosstalk condition.

Description

Antenna code word cooperative optimization method for multi-antenna transmission diversity

Technical Field

The invention relates to the technical field of multi-antenna communication, in particular to an antenna code word collaborative optimization method for multi-antenna transmit diversity.

Background

In the field of multi-antenna transmission systems, there is a problem that non-orthogonal codewords can cause severe crosstalk.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides an antenna code word collaborative optimization method for multi-antenna transmission diversity, which is applied to a multi-antenna transmission system to realize full-rate full-diversity transmission of signals through multi-antenna code word collaborative optimization allocation so as to realize full-diversity gain and full-rate transmission of the transmission system in the multi-antenna transmission system, obviously reduce the calculated amount, solve the adverse effect of non-orthogonal code words in multi-antenna transmission diversity transmission and effectively improve the crosstalk condition.

The purpose of the invention is realized by the following technical scheme:

an antenna code word collaborative optimization method for multi-antenna transmission diversity comprises the following steps:

s1, selecting a coding matrix of the multi-antenna transmission diversity;

s2, analyzing the orthogonality of the code words in the coding matrix;

s3, designing a transmitting antenna structure suitable for the quasi-orthogonal coding matrix;

s4, calculating the isolation between the transmitting antenna array surfaces;

s5, code word optimal allocation based on the isolation degree of the transmitting antenna array surface;

and S6, the method is suitable for the optimized transmission of the quasi-orthogonal coding matrix.

Further, in step S1, according to the number m of transmitting antennas, one matrix is selected from the STBC coding matrices, and is used as a coding matrix of the multi-antenna transmit diversity, denoted as G; the matrix G maximizes the transmit diversity gain when the code rate is not less than the set code rate value R, that is: the number of non-orthogonal vector logarithms in the coding matrix G is reduced as much as possible; and the code rate R is expressed as: after a certain coding matrix is adopted, if K symbols to be transmitted are transmitted through T time slots, the code rate of the coding matrix is R ═ K/T.

Further, in step S2,

the orthogonality analysis method is described below:let v be N columns of the coding matrix G, when i is 1, 2, 3_iThe ith column of G. Calculating v_iAnd v_iInner product of (2)<v_i，v_j>I, j ═ 1, 2, 3.., N; i ≠ j. If it is<v_i，v_j>0 means that the i-th and j-th columns are orthogonal. If it is<vi，vj>Not equal to 0, it means that the i-th and j-th columns are not orthogonal. That is, two columns of the code matrix having an inner product of 0 are orthogonal to each other, and two columns having an inner product of not 0 indicate non-orthogonality.

As for the coding matrix (4),

<v₁，v₂>＝<v₁，v₃>＝<v₂，v₄>＝<v₃，v₄>0. I.e. v₁、v₂Code words being mutually orthogonal, v₁、v₃Are mutually orthogonal, v₂、v₄Are mutually orthogonal, v₃、v₄Are mutually orthogonal. While<v₂，v₃>，<v₁，v₄>Not equal to 0, i.e. v₂、v₃Code word of v₁、v₄Are non-orthogonal.

Further, in step S3, a transmitting antenna structure is designed according to the matrix G, the antenna structure is designed as a regular N-prism with a regular N-polygon cross section and a rectangular longitudinal section, and a single antenna or an array antenna is placed on each of the N side faces.

Further, in step S4, according to the antenna array pattern, the isolation between the transmitting antenna array surfaces is obtained;

the efficient and simplified isolation calculation method is described as that a unit normal vector facing outwards is made on the antenna array surface, and in the range of 0- α -180 degrees, the closer the normal vector included angle α of the two surfaces is to 180 degrees, the more difficult the transmitted signal is to be received by the same receiver at the same time, and the higher the isolation of the two antenna surfaces is.

Setting an antenna plane as plane A, theThe outward-facing normal vector is

Let an antenna face outward normal vector be

According to the formula

To find

And

the isolation degree of the two maximum surfaces with the included angle α is highest, the isolation degree of each array surface is obtained, the antenna surface is set as the surface S, and the isolation degree of each surface antenna can be obtained as the following table 2:

TABLE 2 isolation of antennas on each side

α	Antenna surface	Antenna surface
			α₁	S_{a_1}	S_{b_1}
a₂	S_{a_2}	S_{b_2}
			…	…	…
a_i	S_{a_i}	S_{b_i}
			…	…	…
α_L	S_{a_L}	S_{b_L}

Wherein i is more than or equal to 1 and less than or equal to L, α₁＞α₂＞…＞α_i＞…＞α_L

α_i≠b_i。

Further, in step S5, according to the analysis of the inter-symbol interference effect of the non-orthogonal code word of S2, the receiving end does not receive the non-orthogonal code words at the same time, or can receive the orthogonal code words while receiving the non-orthogonal code words;

according to the antenna isolation tables of all surfaces obtained in the step S3, distributing the code words, placing the non-orthogonal code words on the antenna surface with high isolation, deleting the occupied antenna surface from the isolation tables in order to prevent the same antenna surface from being repeatedly distributed to two groups of different code words, wherein the antenna isolation tables are required to be updated when the code words are distributed once, and then re-distributing the next group of non-orthogonal code words; the algorithm is described as follows:

1) for the coding matrix G, orthogonality analysis is carried out on the coding matrix G, and a non-orthogonal code word pair (v) can be obtained_i，v_j) I, j ═ 1, 2, 3.., N; i ≠ j, using Q_lWhere

l

1, 2, 3, M denotes a momentThe number of the array G non-orthogonal code word pairs;

2) let l equal to 1;

3) according to Table 2, a first set of non-orthogonal codewords is paired to Q_lAssigned to the antenna pair with the highest isolation (S)_{a_1}，S_{b_1}) Transmitting;

4) antenna S_{a_1}And an antenna S_{b_1}Deleting the code words from the antenna isolation table to prevent the same antenna surface from being repeatedly distributed with the code words, and updating the antenna isolation table, as shown in the following table 3;

TABLE 3 isolation degree meter for each antenna

α	Antenna surface	Antenna surface
			α₂	S_{a_2}	S_{b_2}
…	…	…
			α_i	S_{a_i}	S_{b_i}
…	…	…
			α_L	S_{a_L}	S_{b_L}

5) Let l be l +1, if l > M, the codeword assignment ends, otherwise, go to step 3).

Further, in step S6, when the quasi-orthogonal coding matrix is applied to the multi-carrier OFDM system, QAM modulation is performed on the signal to output constellation points, then the coding matrix G selected in S1 is used to perform STBC point-by-point coding on the constellation points, and after IFFT is performed, the signal is transmitted by using the antenna structure in step S3.

Further, in step S6, when the quasi-orthogonal coding matrix is applied to the single carrier SC-FDMA system, the signal is QAM-modulated to output constellation points, after DFT and IFFT are performed, the good coding matrix G selected in S1 is used to perform STBC block-by-block coding on each OFDM symbol, and then the antenna structure in step S3 is used to transmit the signal.

The invention has the beneficial effects that:

(1) the invention is applied to a multi-antenna transmission system, realizes full-rate full-diversity transmission of signals through multi-antenna code word collaborative optimization allocation, achieves full-diversity gain and full-rate transmission of the transmission system in the multi-antenna transmission system, obviously reduces the calculated amount, solves the adverse effect of non-orthogonal code words in multi-antenna transmission diversity transmission, and can effectively improve the crosstalk condition.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a block diagram of an Alamouti code transmitter;

FIG. 2 is a block diagram of an OFDM system;

FIG. 3 is a block diagram of SC-FDMA;

fig. 4 is a receiving end signal constellation (transmitting orthogonal code word);

FIG. 5 is a receiving end signal constellation (transmitting non-orthogonal codewords);

fig. 6 is a receiving end signal constellation diagram (the transmitting signal is an orthogonal code word and a non-orthogonal code word);

FIG. 7 is a schematic diagram of a single-sided antenna array;

fig. 8 is a schematic cross-sectional view of an antenna device (N-4);

fig. 9 is a schematic longitudinal sectional view of an antenna device (N-4);

fig. 10 shows an STBC non-orthogonal codeword optimized antenna apparatus (N-4);

FIG. 11 is a schematic diagram of isolation determination;

fig. 12 is a block diagram of OFDM transmitting end signal processing;

FIG. 13 is a block diagram of SC-FDMA transmitter signal processing;

FIG. 14 is a flow chart of STBC non-orthogonal codeword optimization;

fig. 15 is a quasi-orthogonal space-time coding 4 transmitting antenna optimization device;

fig. 16 is a quasi-orthogonal space-time coding 8 transmitting antenna optimization device.

Detailed Description

The technical solutions of the present invention are further described in detail below with reference to the accompanying drawings, but the scope of the present invention is not limited to the following. All of the features disclosed in this specification, or all of the steps of a method or process so disclosed, may be combined in any combination, except combinations where mutually exclusive features and/or steps are used.

Any feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.

Specific embodiments of the present invention will be described in detail below, and it should be noted that the embodiments described herein are only for illustration and are not intended to limit the present invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to one of ordinary skill in the art that: it is not necessary to employ these specific details to practice the present invention. In other instances, well-known circuits, software, or methods have not been described in detail so as not to obscure the present invention.

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Before describing the embodiments, some necessary terms need to be explained. For example:

if the terms "first," "second," etc. are used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a "first" element discussed below could also be termed a "second" element without departing from the teachings of the present invention. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.

The various terms appearing in this application are used for the purpose of describing particular embodiments only and are not intended as limitations of the invention, with the singular being intended to include the plural unless the context clearly dictates otherwise.

When the terms "comprises" and/or "comprising" are used in this specification, these terms are intended to specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence and/or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

As shown in fig. 1 to 16, an antenna codeword collaborative optimization method for multi-antenna transmit diversity includes:

s1, selecting a coding matrix of the multi-antenna transmission diversity;

s2, analyzing the orthogonality of the code words in the coding matrix;

s4, calculating the isolation between the transmitting antenna array surfaces;

Further, in step S2,

the orthogonality analysis method is described below: let v be N columns of the coding matrix G, when i is 1, 2, 3_iThe ith column of G. Calculating v_iAnd v_iInner product of (2)<v_i，v_j>I, j ═ 1, 2, 3.., N; i ≠ j. If it is<v_i，v_j>0 means that the i-th and j-th columns are orthogonal. If it is<v_i，v_j>Not equal to 0, it means that the i-th and j-th columns are not orthogonal. That is, two columns of the code matrix having an inner product of 0 are orthogonal to each other, and two columns having an inner product of not 0 indicate non-orthogonality.

As for the coding matrix (4),

Further, in step S3, a transmitting antenna structure is designed according to the matrix G, the antenna structure is designed as a regular N-prism with a regular N-polygon cross section and a rectangular longitudinal section, and a single antenna or an array antenna is placed on each of the N side faces. A single-sided antenna array schematic is shown in fig. 7. Where N is equal to the number of column vectors of matrix G. For example, when N is 4, the antenna device has a cross section as shown in fig. 8, a longitudinal section as shown in fig. 9, and an antenna device as shown in fig. 11.

A certain antenna surface is set as a surface A, and the outward normal vector of the surface is

Let an antenna face outward normal vector be

According to the formula

To find

And

TABLE 2 isolation of antennas on each side

α	Antenna surface	Antenna surface
			α₁	S_{a_1}	S_{b_1}
α₂	S_{a_2}	S_{b_2}
			…	…	…
α_i	S_{a_i}	S_{b_i}
			…	…	…
α_L	S_{a_L}	S_{b_L}

Wherein i is more than or equal to 1 and less than or equal to L, α₁＞α₂＞…＞α_i＞…＞α_L，

α_i≠b_i。

1) for the coding matrix G, orthogonality analysis is carried out on the coding matrix G, and a non-orthogonal code word pair (v) can be obtained_i，v_j) I, j ═ 1, 2, 3.., N; i ≠ j, using Q_lRepresenting, where

l

1, 2, 3, M represents the number of non-orthogonal codeword pairs of the matrix G;

2) let l equal to 1;

4) antenna S_{a_1}And an antenna S_{b_1}Deleting from the antenna isolation table to prevent the same antenna surface from being repeatedly allocated with code words and updating the antenna simultaneouslyLine isolation tables, as shown in table 3 below;

TABLE 3 isolation degree meter for each antenna

Further, in step S6, when the quasi-orthogonal coding matrix is applied to the multi-carrier OFDM system, QAM modulates the signal to output constellation points, then uses the coding matrix G selected in S1 to perform STBC point-by-point coding on the constellation points, and uses the antenna structure in step S3 to transmit the signal after IFFT, as shown in fig. 12.

Further, in step S6, when the quasi-orthogonal coding matrix is applied to the single carrier SC-FDMA system, the signal is QAM-modulated to output constellation points, after DFT and IFFT are performed, the good coding matrix G selected in S1 is used to perform STBC block-by-block coding on each OFDM symbol, and then the antenna structure in step S3 is used to transmit the signal, as shown in fig. 13.

The concept of space-time coding was first proposed in 1987 by Winter, and the design criteria for space-time coding were given by Guey et al and Tarokh et al, respectively. The space-time coding is a new coding and signal processing technology in wireless communication, and the space-time coding simultaneously utilizes two dimensions of time and space to construct code words, so that the transmission diversity degree and the degree of freedom provided by a MIMO system consisting of multiple transmitting and multiple receiving antennas can be better utilized, the information transmission efficiency can be improved under the condition of not increasing the transmitting power, and the information transmission performance can be improved.

1) Space-time code design criteria:

rank and determinant criterion:

in a MIMO system, assuming that symbols are to be transmitted from N antennas in T time slots, a tx codeword matrix of T × N may be defined as G¹After the transmitted code word is transmitted through the channel, the decoding of the receiving end may be wrong due to the influence of noise and fading factors, so the decoded code word matrix G is set²Comprises the following steps:

defining an error matrix:

D(G¹，G²)＝G²-G¹( 1)

let A (G)¹，G²)＝D(G¹，G²)H·D(G¹，G²)＝(G²，G¹)H·(G²，G¹)

The diversity gain is equal to matrix a (G)¹，G²) Is multiplied by the number of receive antennas, and the coding gain is related to the matrix a (G)¹，G²) Is related to the determinant value of.

2) Design of QOSTBC:

the codeword matrix for Alamouti code transmission is:

the block diagram of the Alamouti code transmitter is shown in FIG. 1, which is easily demonstrated by the above formula, G_Alamouti ^HG_Alamouti＝(|x₁|²+|x₂|²)I₂I.e. the column vectors of the matrix of code words are mutually orthogonal, the Alamouti code is an orthogonal code word. Defining a space-time block code, when K symbols are transmitted through T slots, the code rate of the space-time block code is:

the code rate of the Alamouti code is 1.

But when the number of transmitting antennas exceeds 2, it is difficult to obtain a space-time code of a full-rate complex orthogonal design.

In order to solve the problem, the quasi-orthogonal space-time code is designed by Jafarkhani and the like according to the space-time code proposed by Alamouti, and the code rate can reach 1 when the transmitting antenna exceeds 2.

By Alamouti coding, quasi-orthogonal code words can be designed as follows:

QOSTBC has many coding matrix structures similar to equation (3), some commonly used structures are as follows:

for QOSTBC for 3 transmit antennas, a 4 × 3 matrix can be constructed according to equations (4) to (7), e.g., a matrix can be constructed according to equation (4):

since 4 symbols are transmitted in 4 slots, the matrix rate is 1 full rate.

Equations (4) to (7) are constructed such that a 4 × 4 matrix can be constructed from two 2 × 2 matrices, thereby keeping the transmission rate constant at 1. Similarly, a 2N × 2N matrix may be constructed with any two N × N matrices.

3) Distinction between single-carrier systems and multi-carrier systems

Fig. 2 is a block diagram of an OFDM system, and fig. 3 is a block diagram of an SC-FDMA system.

An OFDM (Orthogonal Frequency Division Multiplexing) system performs point-by-point STBC coding on each constellation point after QAM is modulated at a transmitting end, and ML decoding is directly performed after FFT at a receiving end, whereas an SC-FDMA (Single-carrier Frequency-Division Multiple Access) system performs block Division, DFT and IFFT on the constellation point after QAM is modulated at the transmitting end, then performs STBC block-by-block coding on each OFDM symbol, does not perform ML decoding at the receiving end, but directly performs decoding in MMSE equalization.

Defining H as the channel response matrix, σ²Is the signal to noise ratio. MMSE equalization considers both interference and noise suppression and decoding of space-time coding. The weighting matrix of the MMSE equalizer is W_MMSE＝(H^HH+σ²I)^-1H^H. The signal matrix output by MMSE equalization is

The SC-FDMA technology is generally adopted in an uplink system of LTE. Compared with OFDM modulation, the PAPR (peak-to-average power ratio) of SC-FDMA can be obviously inhibited, the requirement of equipment on power amplification is reduced, and the power amplification efficiency is greatly improved. Meanwhile, compared with the OFDM system, the SC-FDMA system also utilizes efficient FFT operation, transmission is realized in a block structure, and cyclic extension (guard interval) is also added to a single block to mitigate inter-block interference.

For 4-antenna space-time coding, the full rate is somewhat non-orthogonal and cannot achieve full diversity gain. Jafarkhani proposes to put x before transmission₃，x₄The full diversity gain can be realized by constellation rotation processing. I.e. define

Where theta denotes the angle of rotation of the constellation. However, not all modulation schemes have an optimal rotation angle to achieve full diversity gain, and the codeword is only suitable for use in multi-carrier transmission systems. If the code word orthogonality can not be realized by finding the optimal rotation angle, the system cannot reach the full diversity gain, and the decoding condition of the scheme is limited, and ML (maximum-likelihood decoding) must be used, so that the scheme cannot be expanded to the case of single carrier, and is not suitable for the application of emphasizing the communication distance.

In SC-FDMA systems, non-orthogonal codewords can cause severe crosstalk.

Under the condition of no rotation, a signal constellation diagram obtained at a receiving end when a transmitting end transmits non-orthogonal code words or orthogonal code words under the conditions of 2 transmission and 1 reception in a single carrier system and QPSK modulation is obtained.

Setting the input signal d (T) as the time interval T for analyzing the problem conveniently_sIs made up of a series of impulses delta (t), i.e.

In the formula: a is_nIs nT_sSymbol sign of time, T_sIs the symbol width.

If let the impulse response of the baseband transmission system be h (t), then

The sampling time t is kT_s

Wherein a is_kh (0) denotes the response of the system for the k-th symbol at t ═ kT_sSampled value of time, sigma_n≠ka_nh[(k-n)T_s]Indicating the response of the system to other symbols at t-kT_sThe sampled value of the time instant is also called intersymbol interference. n is_k(kT_s) Indicating the response of the filter at the receiving end to the channel noise at t ═ kT_sThe sample value of the time instant.

The signal value of the receiving end is actually the superposition of the signal value of the receiving end, the intersymbol interference value and the noise value.

As can be seen from fig. 4 and 5, the dots of fig. 5 are the result of adding the dots of fig. 4. It is clear that non-orthogonal codewords give severe intersymbol interference to the system.

For a 3-transmit-1-receive communication system, the transmitted signal includes both orthogonal code words and non-orthogonal code words. The corresponding signal constellation received by the receiving end is as shown in fig. 5.

The EVM of the receiving end in the above three cases can be obtained as shown in table 1, and it can be found that the system performance is very poor when the signal is transmitted in the case of 2 d, and although the non-orthogonal code exists in the case of 3 d, the performance is not as good as the case of transmitting only the orthogonal code in the case of 2 d, the crosstalk can be effectively improved by introducing the corresponding orthogonal code.

TABLE 1 RxEVM for different transmit antenna pattern systems

Wherein

Where R is the received signal matrix and X is the transmitted signal matrix. The RxEVM, that is, the receiving end EVM (Error Vector Magnitude, Vector Error amplitude), is defined as the ratio of the average power of the receiving end Error Vector signal to the average power of the reference signal, and is an index capable of comprehensively measuring the signal amplitude Error and the phase Error.

Example 1

As for the 4 transmit antenna arrangement, the codeword may be selected

Wherein<v₁，v₂>＝<v₁，v₃>＝<v₂，v₄>＝<v₃，v₄>＝0，<v₂，v₃>，<v₁，v₄>≠0，

I.e. v₁And v₄Code word of v₂And v₂Are non-orthogonal.

The antenna structure can be designed to be a square cross section, a rectangular regular quadrangular prism longitudinal section, the structure diagram is shown in fig. 15, the position of the definition mark 1 is a number 1 antenna surface, and the number 2, 3 and 4 antenna surfaces are arranged in sequence according to the clockwise direction.

Isolation analysis is carried out on the antenna device, and as the device is a regular quadrangular prism, it can be obviously obtained that the isolation of the No. 2 antenna surface and the No. 3 antenna surface parallel to the No. 2 antenna surface is the highest, and the isolation of the No. 4 antenna surface parallel to the No. 2 antenna surface is the highest.

Optimally distributing code words to obtain non-orthogonal code words v₁And v₄Respectively transmitting on the antennas 1 and 3 with the highest isolation, and transmitting another non-orthogonal code word pair v₂And v₃And respectively placed on the 2 and 4 with the highest isolation degree for emission.

Generally, signals transmitted by two adjacent surface antennas can be received, and the signals transmitted by any two adjacent antenna surfaces are necessarily a pair of orthogonal signals. In special cases, signals transmitted by three surface antennas are received, and the middle of the signals contains orthogonal code words, so that crosstalk can be effectively avoided.

8 the transmit antennas may select the QOSTBC 8 transmit antenna coding matrix proposed by Jafarkhani:

since 6 symbols are transmitted in 8 slots, the code rate is R3/4.

Let v_iRepresentation matrix G_8，8The columns of (1) then have:

<v₁，v_i>＝0，i≠5

<v₂，v_i>＝0，i≠6

<v₃，v_i>＝0，i≠7

<v₄，v_i>＝0，i≠8

<v₅，v_i>＝0，i≠1

<v₆，v_i>＝0，i≠2

<v₇，v_i>＝0，i≠3

<v₈，v_i>＝0，i≠4

then the non-orthogonal code word pair is (v) respectively₁，v₅)、(v₂，v₆)、(v₃，v₇)、(v₄，v₈).

The cross section of the antenna structure is designed to be a regular octagon, the longitudinal section of the antenna structure is designed to be a rectangular regular octagon, the antenna structure is arranged on the surface 1 as shown in figure 16, the positions are marked as in figure 14, and the positions are sequentially the positions of the surfaces 2, 3, 4, 5, 6, 7 and 8 according to the clockwise direction, included angles α between normal vectors of the antennas facing the antenna array are respectively calculated, the larger the included angle is, the higher the isolation degree is, and the isolation degree of the antennas on each surface is obtained as shown in table 4.

TABLE 4 quasi-orthogonal space-time coding 8 transmitting antenna optimization device isolation

Will not orthogonal code word pair (v)₁，v₅) Transmitting on 1, 5 antenna surfaces respectively, (v)₂，v₆) Transmitting on 2 and 6 antenna surfaces respectively, (v)₃，v₇) Transmitting on 3, 7 antenna surfaces respectively, (v)₄，v₈) And respectively transmitting on 4 and 8 antenna surfaces.

In general, signals from 4 antenna surfaces can be received, code words transmitted by the four antenna surfaces are orthogonal pairwise, signals from 3 or 5 antenna surfaces can be received in special cases, and transmitted code words are orthogonal pairwise for 3 transmitting antennas. For signals transmitted by 5 antenna surfaces, only one pair of antennas transmits code words which are not orthogonal, and other antennas are mutually orthogonal, so that the influence caused by the non-orthogonal antennas can be effectively avoided.

In other technical features of the embodiment, those skilled in the art can flexibly select and use the features according to actual situations to meet different specific actual requirements. However, it will be apparent to one of ordinary skill in the art that: it is not necessary to employ these specific details to practice the present invention. In other instances, well-known algorithms, methods or systems have not been described in detail so as not to obscure the present invention, and are within the scope of the present invention as defined by the claims.

For simplicity of explanation, the foregoing method embodiments are described as a series of acts or combinations, but those skilled in the art will appreciate that the present application is not limited by the order of acts, as some steps may occur in other orders or concurrently depending on the application. Further, those skilled in the art should also appreciate that the embodiments described in the specification are preferred embodiments and that the acts and elements referred to are not necessarily required in this application.

Those of skill in the art would appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The disclosed systems, modules, and methods may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units may be only one logical division, and there may be other divisions in actual implementation, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be referred to as an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and the parts displayed as units may or may not be physical units, may be located in one place, or may also be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

It will be understood by those skilled in the art that all or part of the processes in the methods for implementing the embodiments described above can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium, and when executed, the program can include the processes of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a ROM, a RAM, etc.

The foregoing is illustrative of the preferred embodiments of this invention, and it is to be understood that the invention is not limited to the precise form disclosed herein and that various other combinations, modifications, and environments may be resorted to, falling within the scope of the concept as disclosed herein, either as described above or as apparent to those skilled in the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. An antenna code word collaborative optimization method for multi-antenna transmit diversity is characterized by comprising the following steps:

s1, selecting a coding matrix of the multi-antenna transmission diversity;

s2, analyzing the orthogonality of the code words in the coding matrix;

s4, calculating the isolation between the transmitting antenna array surfaces;

2. The method of claim 1, wherein in step S1, according to the number m of transmitting antennas, selecting one matrix from STBC coding matrices as the coding matrix of multi-antenna transmit diversity, denoted as G; the matrix G maximizes the transmit diversity gain when the code rate is not less than the set code rate value R, that is: the number of non-orthogonal vector logarithms in the coding matrix G is reduced as much as possible; and the code rate R is expressed as: after a certain coding matrix is adopted, if K symbols to be transmitted are transmitted through T time slots, the code rate of the coding matrix is R ═ K/T.

3. The method for antenna codeword cooperative optimization for multi-antenna transmit diversity according to claim 1, wherein in step S2,

As for the coding matrix (4),

<v₁，v₂>＝<v₁，v₃>＝<v₂，v₄>＝<v₃，v₄>0. I.e. v₁、v₂Code words being mutually orthogonal, v₁、v₃Are mutually orthogonal, v₂、v₄Are mutually orthogonal, v₃、v₄Code word mutualAre orthogonal. While<v₂，v₃>，<v₁，v₄>Not equal to 0, i.e. v₂、v₃Code word of v₁、v₄Are non-orthogonal.

4. The antenna codeword cooperative optimization method for multi-antenna transmit diversity according to claim 1, wherein in step S3, the transmit antenna structure is designed according to the matrix G, the antenna structure is designed as a regular N-sided prism with a cross section of a regular N-sided polygon and a longitudinal section of a rectangular N-sided polygon, and a single antenna or an array antenna is respectively placed on N side faces.

5. The method for antenna codeword cooperative optimization for multi-antenna transmit diversity according to claim 1, wherein in step S4, the isolation between transmit antenna wavefronts is determined according to the antenna array pattern;

Let an antenna face outward normal vector be

According to formula

To find

And

angle αα, the maximum isolation of the two surfaces is the highest, the isolation between the front surfaces is calculated, the antenna surface is the surface S, and the isolation table of each surface antenna can be obtained as the following table 2:

TABLE 2 isolation of antennas on each side

α Antenna surface Antenna surface α₁ S_{a_1} S_{b_1} α₂ S_{a_2} S_{b_2} ... ... ... α_i S_{a_i} S_{b_i} ... ... ... α_L S_{a_L} S_{b_L}

a_i≠b_i。

6. The method of claim 1, wherein in step S5, according to the analysis of the inter-symbol interference effect of the S2 non-orthogonal codewords, the receiving end does not receive the non-orthogonal codewords at the same time, or can receive the orthogonal codewords at the same time;

according to the antenna isolation tables of all surfaces obtained in the step S3, distributing the code words, placing the non-orthogonal code words on the antenna surface with high isolation, deleting the occupied antenna surface from the isolation tables in order to prevent the same antenna surface from being repeatedly distributed to two groups of different code words, wherein the antenna isolation tables are required to be updated when the code words are distributed once, and then re-distributing the next group of non-orthogonal code words;

the algorithm is described as follows:

1) for the coding matrix G, orthogonality analysis is carried out on the coding matrix G, and a non-orthogonal code word pair (v) can be obtained_i，v_j) I, j ═ 1, 2, 3.., N; i ≠ j, using Q_lRepresenting, where l 1, 2, 3, M represents the number of non-orthogonal codeword pairs of the matrix G;

2) let l equal to 1;

TABLE 3 isolation degree meter for each antenna

α Antenna surface Antenna surface α₂ S_{a_2} S_{b_2} ... ... ... α_i S_{a_i} S_{b_i} ... ... ... α_L S_{a_L} S_{b_L}

7. The method of claim 1, wherein in step S6, when the quasi-orthogonal coding matrix is applied in the multi-carrier OFDM system, the signal is QAM-modulated to output constellation points, then the coding matrix G selected in S1 is used to STBC point-by-point code the constellation points, and after IFFT is performed, the signal is transmitted by the antenna structure in step S3.

8. The method of claim 1, wherein in step S6, when the quasi-orthogonal coding matrix is applied in a single carrier SC-FDMA system, the signal is QAM modulated to output constellation points, after DFT and IFFT, the coding matrix G selected in S1 is used to perform STBC block-by-block coding on each OFDM symbol, and then the antenna structure in step S3 is used to transmit the signal.